The trailer...I will see this movie!

[RJNorton]

There are a lot of descriptions, but here's one that seems to be fairly consistent with many. It comes from a gentleman named Horace White regarding a speech Lincoln made in Springfield in 1854:

"I observed that, although awkward, he was not in the least embarrassed. He began in a slow and hesitating manner, but without any mistakes of language, dates, or facts. It was evident that he had mastered his subject, that he knew what he was going to say, and that he knew he was right. He had a thin, high-pitched falsetto voice of much carrying power, that could be heard a long distance in spite of the bustle and tumult of a crowd. He had the accent and pronunciation peculiar to his native State, Kentucky."

Although White's description was made many years after the event, I have also seen several references to the "terrific carrying power" of Lincoln's voice at Gettysburg. Regarding the Gettysburg Address, Pennsylvania Governor Andrew G. Curtin said, "He pronounced that speech in a voice that all the multitude heard."

Thank you to Gene for sending this link.